OH2 R -N N: Mg2 -N `N- MeO His OC20H29 R = CH3 (Chl-a) = CHO (Chl-b)

TLNEVE-++ACOD n t t G 80. n Tuu 30 BRE 40 20 Oc C d 4000 a b 3600 (a) CH-CH₂-CH₂-CH₂-C=CH (B) CH-CH2-CH2-CH2-CH2-CI (c) CH-CH₂-CH₂-CH₂-CH-CH₂ (d) CH,CH2-CH2-CH2-CH2-CH3 2000 2600 Wa venumberc 2000 1600 1000 600

2. The following diagram shows the straight-chain structure of an N-acetyl aminoheptose that is found in certain plants including avocado (Persea Americana). CHOH CH2OH CH,OH O: O: HO- но -HO- HO H но -HO- H- NHAC NHAC ACHN OH HN H- HO- HO CH2OH CHOH CH20H HO HO. Structure B Structure C Structure A OH OH CHOH CH2OH CH OH HO H HO H HO- H OH HO- HO H- -NHAC ACHN- ACHN HO- H OH HO ČHOH CH2OH CH2OH Structure D Structure E Structure F Which of the Fischer projections (A-F) matches the skeletal formula shown? Structure A Structure B Structure C Structure D Structure E O Structure F (1 mark) 王 HI

Methyl isocyanate, CH3 -N= C = O, is used in the industrial synthesis of a type of pesticide and herbicide known as a carbamate. As a historical note, an industrial accident in Bhopal, India, in 1984 resulted in leakage of an unknown quantity of this chemical into the air. An estimated 200,000 people were exposed to its vapors, and over 2000 of these people died. Q.) Methyl isocyanate reacts with strong acids, such as sulfuric acid, to form a cation. Will this molecule undergo protonation more readily on its oxygen or nitrogen atom? In considering contributing structures to each hybrid, do not consider structures in which more than one atom has an incomplete octet